1. Field of the Invention
This invention relates generally to a textile fabrication apparatus, and more specifically to a beam winder apparatus for aligning and winding a plurality of textile yarns, threads or filaments on a spool or beam.
2. Description of Background Art
An apparatus for winding a plurality of unidirectionally aligned threads, yarns or filaments onto a beam is well known in the art. This type of apparatus is typically referred to as a “beam winder” or a “warping machine.” (the aligned yarns often form the warp direction of a subsequently fabricated fabric). In general, a beam winder (1) unwinds a large number of yarns from spools or bobbins on which the yarns are individually wound, (2) aligns the yarns from each spool in a common direction (typically horizontal) in a planar relationship, and (3) winds the aligned planar plurality of yarns on to a beam.
The resulting beams of aligned yarns are then utilized in subsequent textile processing operations. For example, the aligned yarns from several beams may be commingled to generate wider beams of aligned yarns with a denser concentration of yarns (typically measured in yarns per inch). The beams may also be utilized in a loom, wherein the yarns are unwound from the beam and weft or fill fibers are interwoven among the aligned yarns to create a woven fabric. Additionally, transversely aligned (weft) yarns or a non-woven matt may be adhesively bonded to the aligned planar yarns as they are unwound from the beam to create a non-woven fabric material.
A typical beam winder includes a longitudinally-extending framework. A beam coupled with a motor is positioned at one end of the winder to receive the plurality of aligned planar yarns. A comb is positioned upstream from the beam. The comb includes a large number of holes (one for each individual yarn) through which the end of each individual yarn is threaded. Each hole is positioned to align the yarn passing through in the horizontal direction relative to the other yarns. A series of racks configured with a certain number of yarn spools are positioned upstream of the comb. Given (i) the large number of spools (typically hundreds), (ii) the longitudinal orientation of the framework, and (iii) the required spacing between adjacent spools due to the nominal diameter of the spools, it is necessary to utilize a number of racks positioned at differing distances from the comb. Often as a yarn passes from its spool to the comb it passes through a number of eyelets that help to support the yarn and the comb and prevent the yarn from tangling with the other yarns. During machine setup, yarn from each spool must be individually and manually threaded through each eyelet and through its specific opening in the comb. Given the hundreds of spools typically utilized, the setup process is both costly and time consuming.
Given the varying distances that different yarns must travel from their spools to the comb and then to the beam, different amounts of force are required to pull each yarn onto the beam. The required force is primarily related to overcoming the weight of any unsupported unwound yarn hanging between the spool and the comb; the friction resulting from the yarn being pulled through the eyelets, and air friction related to the length of the yarn. Accordingly, a greater force is required to pull a yarn from a spool as the distance between the spool and the comb increases. The force necessary to move a yarn ultimately relates to the residual tension of a yarn as it is wrapped onto the beam. Simply, the tension in a yarn is equal to the force required to pull it divided by the cross sectional area of the yarn.
In some beam winders designed for use with monofilaments threads or threads comprised of a plurality of continuous filaments (not spun yarns), a heater is disposed between the comb and the beam. The heater momentarily exposes the threads to a high level of heat while the threads are stretched to both increase the strength of the threads and reduce the diameter of the threads to a desired denier.
Current art beam winders do not have the ability to preshrink the yarns during the beam winding process, so when sheets of aligned preshrunk yarns are desired, the individual spools of yarn are preshrunk prior to use on the beam winder or the yarn sheet winding of a beam is preshrunk in a separate operation. Separate preshrinking operations add to the cost of the products produced from the yarn sheet and depending on how the preshrink process is performed, the shrinkage may not be uniform from yarn to yarn or from one section of a yarn to another.
Aligned yarn sheets of preshrunk yarns are often essential, however, in the production of non-woven fabrics, especially when the yarns utilized in the non-woven fabric are of the spun-type. In pressurized lamination processes often used to laminate weft fibers or a non-woven mat to the warp fibers of a yarn sheet, relatively high temperatures may be utilized to liquefy a hot melt adhesive. If the constituent fibers of yarn sheet have not been preshrunk, they can shrink during the lamination process and can distort the weft fibers or non-woven mat to which they are adhesively attached resulting in non-woven fabrics that are not aesthetically acceptable. Further, even when the yarn sheet has been preshrunk, non-uniform, unacceptable non-woven fabrics can result, if the yarns comprising the yarn sheet were not shrunk uniformly.